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Optical disk apparatus and address detection method

an optical disk and address detection technology, applied in the field of reproducing address information, can solve the problems of low reliability and difficulty in correctly reading out address data

Inactive Publication Date: 2005-12-08
KK TOSHIBA
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

[0011] The object of the present invention is to provide an optical disk apparatus and an address detection method, which are capable of correctly reproducing address data from a land & groove recording-type optical disk on which address data is recorded by a wobble modulation method.

Problems solved by technology

In the pre-pit method, a record signal has information at an edge portion thereof, so the reliability tends to be low.
However, if address data is to be recorded by the wobble modulation scheme on the land & groove recording-type optical disk, the following drawback arises.
It is thus difficult to correctly read out the address data.

Method used

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  • Optical disk apparatus and address detection method
  • Optical disk apparatus and address detection method
  • Optical disk apparatus and address detection method

Examples

Experimental program
Comparison scheme
Effect test

example 1

OF OPERATION

[0089] When the groove (land) track is reproduced, GTr (LTr) is output as the track address.

[0090] (1) At the time when the previous error detection result (stored in memory 76) is “Low” (no error):

[0091] When GTr=LTr=Tr′, the error detection result is set to be “Low”. In other cases, the error detection result is set to be “High” (presence of error).

[0092] (2) At the time when the previous error detection result is “High”:

[0093] When GTr=LTr, the error detection result is set to be “Low”. In other cases, the error detection result is set to be “High”.

[0094] The operation of the track address reproducing unit 74 is not limited to the above, and the following operations may be executed.

example 2

OF OPERATION

[0095] (1) At the time when the previous error detection result is “Low”:

[0096] When GTr=Tr′ or LTr=Tr′, the error detection result is set to be “Low”. In other cases, the error detection result is set to be “High” (presence of error). In any case, Tr′ is output as the track address.

[0097] (2) At the time when the previous error detection result is “High”:

[0098] When GTr=LTr, the error detection result is set to be “Low”. In other cases, the error detection result is set to be “High”. When the groove (land) track is reproduced, GTr (LTr) is output as the track address.

example 3

OF OPERATION

[0099] (1) At the time when the previous error detection result is “Low”:

[0100] If at least two of GTr, LTr and Tr′ agree, the error detection result is set to be “Low”. In other cases, the error detection result is set to be “High”. The track address is output in accordance with the decision by majority of the bits of GTr, LTr and Tr′.

[0101] (2) At the time when the previous error detection result is “High”:

[0102] When GTr=LTr, the error detection result is set to be “Low”. In other cases, the error detection result is set to be “High”. When the groove (land) track is reproduced, GTr (LTr) is output as the track address.

[0103] The operation mode of the track address reproducing unit 74 is variable depending on the purpose of use, that is, depending on the level of requirement for the track address. For example, at the time of data recording, Example 1 of Operation is adopted. At the time of data reproduction, Example 2 or 3 of Operation may be adopted.

[0104] In the...

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PUM

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Abstract

An optical disk apparatus comprises a Gray code detector for detecting a Gray code of a track address, a position detector for detecting, as an address uncertain position, a least significant bit of the detected Gray code of the track address and a bit of the detected Gray code of the track address and is higher by one than a bit position of a least significant code bit “1”, and a replacing unit which replaces a bit at the address uncertain position of the land address with a bit at a corresponding position of the groove address of the same track, and replaces a bit at the address uncertain position of the groove address with a bit at a corresponding position of the land address of the same track.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is based upon and claims the benefit of priority from prior Japanese Patent Application No. 2004-169093, filed Jun. 7, 2004, the entire contents of which are incorporated herein by reference. BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates generally to a process of reproducing address information from a recordable optical disk, and more particularly to an optical disk apparatus and an address detection method with enhanced reliability in address data detection. [0004] 2. Description of the Related Art [0005] Data is spirally recorded on an optical disk. In order to enable an optical head to exactly trace the spiral tracks at a time of recording or reproduction, guide grooves are pre-recorded on the recordable optical disk. The grooves that are pre-recorded are wobbled at predetermined cycles. At the time of reproduction, the wobble cycle is measured to detect a scanning ...

Claims

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Application Information

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IPC IPC(8): G11B5/09G11B7/005G11B20/12G11B7/007G11B7/24G11B20/18G11B27/24
CPCG11B7/00718G11B27/24
Inventor KASHIHARA, YUTAKAKOJIMA, TADASHIOGAWA, AKIHITO
Owner KK TOSHIBA